Tubular stock bending machine



Nov. 12, 1968 H. SCHMIDT TUBULAR STOCK BENDING MACHINE 2 Sheets-Sheet 1 Filed Feb. 2, 1967 INVENTOR. 1762225 Ji'fimz a Z.

Nov. 12, 1968 H. SCHMIDT 3,410,125

TUBULAR STOCK BENDING MACHINE Filed Feb. 2, 1967 2 Sheets-Sheet 2 INVENTOR.

nited States Patent v I g 3,410,125" TUBULAR STOCK BENDING MACHINE Hans Schmidt, Aurora, 11]., assignor to'Pines Engineer ng Co., Inc., Aurora, Ill.,*a corporation of Illinois Filed Feb. 2, 1967, Ser. No. 613,563 8 Claims. (Cl. 72--156) ABSTRACT OF THE DISCLOSURE The invention relates to improvements in machines for bending tubular stock and the like. Itincludes a bending die and clamp die and a ram assembly of conventional construction. A wiper die is associated with and is formed to nest at one end in the bending die to insure a smooth undulated bend. This wiper die is mounted that, when the clamp die moves into open position, the wiper die is rotated about the axis of the bending die to such an extent that clearance is afforded to the ram assembly to enable it to more closely approach the bending die than has heretofore been possible with bending machine assemblies of known construction.

It is, therefore, an object of this invention to provide a bending machine of the character referred to.

Another object is to provide a bending machine having a bending die therein, with a wiper die assembly of novel construction.

Another object of the invention is to provide a wiper die of novel construction for a bending machine.

Another object is to provide apparatus of the character referred to which is not expensive or difficult to manufacture and maintain in serviceable condition, and one that is very efficient in use.

The structure by means of which the above noted and other advantages of the invention are attained will be described in the following specification, taken in conjunction with the accompanying drawings, showing a preferred illustrative embodiment of the invention, in which:

FIG. 1 is a plan view of a bending machine embodying the features of the invention, showing the wiper and clamp dies in tube clamping positions;

FIG. 2 is a plan view similar to FIG. 1, showing the wiper dieand clamp die in open positions and the ram advanced;

FIG. 3 is an enlarged sectional plan view of the bending die showing the wiper die, in section, associated therewith;

FIG. 4 is a plan view of the Wiper die;

FIG. 5 is a front elevational view of the wiper die;

FIG. 6 is a rear view of the wiper die; and

FIG. 7 is an end view of the wiper die.

Referring to the representative disclosure of a bending machine as shown in FIGS. 1 and 2, the machine includes a frame structure 11, only partially illustrated, having a nose portion on which a bending die 12 is mounted for rotation in a horizontal plane. The bending die has associated with it a wiper die 13 of novel construction, and a clamp die 14. These dies cooperate to embrace the tail end of a length of stock, such as the tubular stock 15 illustrated in broken lines.

As is well known, machines of this character operate to cause partial rotation, counterclockwise, of the bending die and an associated clamp 16, so as to cause the tubular stock to be bent into a required curvature. The wiper die 13 and associated clamp die 14 function to 3,410,125 Patented Nov. 12, 1968 hold the tail portion of the tubular stock during the bending operation. When a multitude of bends are to be formed in a single length of stock said stock is fed, in measured amounts, forwardly into the clamp and die ram 17 of any conventional constructionis advanced assemblies following each successive bend. To this end a along guide 18 against the tail end of the stock. During such movement, the clamp die 14 is withdrawn from its clamp position. It has been found that in conventional bending machines the forward movement of the ram is limited by the presence of the wiper die which normally lies in its path. As a consequence, it is impossible to perform a bend in the extreme tail-end portion of the stock and such tail portion must subsequently be cut 011. This occasions extra labor and material waste.

The bending machine herein disclosed obviates such material waste and extra labor by affording means whereby the ram can closely approach the bending die and thus permit the performance of a bend in the extreme tail portion of the stock. For this purpose the wiper die 13 is carried on a movable element so as to be moved out of the way of the ram.

More particularly, the wiper die 13 is mounted firmly on a table 19 that is freely rotatable about the axis of the bending die, independently of rotation of said bending die. As best shown in FIGS. 1 and 2, the table 19 includes an annulus 19a that is suitably journalled for free rotation in a horizontal plane on the machine housing nose. The wiper die 13 is suitably secured to the table as by a mounting block 20 and it is formed, in a manner to be described presently, so as to have one end nest snugly in the tube receiving groove 21 of the bending die.

Rotational movement of the table and wiper die may 'be effected by a piston-cylinder assembly 22 connected thereto, as at 23. This piston-cylinder assembly may be hydraulically operated. As shown in FIG. 1, the wiper die 13 is in clamp position whereas in FIG. 2 it is shown in open position. When in clamp position it bears against one side of the tubular stock and the clamp die 14 bears against the opposed side of said stock, thus clamping the stock firmly between them. The clamp die 14 is movable also into an open position as shown in FIG. 2.

When the two dies 13 and 14 are in open positions, the ram 17 may advance closely to the bending die between said wiper die and clamp die, as shown in FIG. 2, so as to thrust the tail portion of the stock 15 forwardly a maximum distance thus leaving no waste tail portion. In fact, a bend may be accomplished in the extreme tail end portion of the tubular stock.

When bends are formed in the stock such bends must be effected without generating any undulations or wrinkles in the tubular stock. Accordingly, the wiper die 13 is formed to fit snugly into and merge with the bending die. This is best illustrated in FIGS. 3 to 7. As there shown, the wiper die comprises a semi-cylindrical length of solid stock having its forward or bending die meeting-end suitably formed to nest into the bending die groove 24. Accordingly, the effective end of the body of the wiper die is cut away, as at 25, to conform substantially to the greatest diameter of the bending die. A nose portion 26 is formed thereon which is contoured to nest in a semi-circular groove 21 of the bending die. This information generates a knife-like terminal edge 27 that merges into the surface of the semi-circular groove 21. As a consequence (see FIG. 3), there is a smooth transition from the wiper die groove to the bending die groove and no undulations are generated in the tubular stock during the bending operation.

Although I have described a preferred embodiment of the invention, in considerable detail, it will be understood that the description thereof is intended to be illustrative, rather than restrictive, as details of the structure disclosed. may be modified ortchanged without departing from the spirit or scope of the invention. Accordingly, I do not desire to be restricted to the exact construction described and shown. I

r I claim: I 1 1. In a bending machine including a bending die, a clamp die and a wiper die, wherein theimprovement comprises, a mountingtor the wiper die which is rotatable about the axis of the bending die, and means operable to rotate" said mounting and wiper die thereon about said 8X18... t i -2. The bending machine recited in claim 1, in which the mounting comprises a plate-like structure arranged beneath the bending die and rotatable independently thereof. r "3. The bending machine recited in claim 1, inwhich the means operable to rotate the wiper die comprises 'a piston-cylinder assembly. '4." Thebendin'g'r'nachine recited in claim 1, in which thebending machine includes 'a reciprocable feed ram and the clamp die and wiper die are movable into positions to enable the ram to closely approach the bending die. 4

5. The bending. machineflrecited in claim 1, in which the wiper die is held stationary during bending movement of the bending die.

6. The bending machine recited in claim 1, in which the wiper die is elongated and; has one end thereof in surface Contact with the bending-die; 1 7 The" bending machine recited in '-"cla1rn 1, 111 'which the bending die includes"a 'matei ialreceiying channel and the wiper die is an elongated' body semi-circular in section and formed "at one end to nest in the bending die channel.

8. The bending. machine recited in claim 1, in which the wiper die comprises an elongatedbody having a knifelikeedge at one-end.-

References Cited- I I V UNITEDSTATES PATENTS 7 2167336 "2/1959; Fuchs f72Q-ld8 2,906,316 9/1959 GeIlaCh 72l58 3,156,287 11/1964 tMunLo 72156 CHARLES 'W." LANHAM, Primary Examiner;

kissis taiitxExzjrinirzer, v 

